1. Field of Invention
This invention relates to telescopic rifle sights, and specifically to a mount which attaches to the top of a rifle and allows a telescopic sight to be offset to one side.
2. Description of Prior Art
It has long been known to attach a telescopic sight to a rifle so that the longitudinal axis of the telescopic sight is aligned with the bore of the rifle barrel. Various methods have been used, with the object generally being to place the telescopic sight directly above the rifle barrel. One result of this placement is that the traditional open sights are partially or completely obscured by the telescopic sight and its mounting hardware. While the loss of the open sights is typically not a problem, it is of great concern when the rifle is used on dangerous game. In game control and hunting situations, dangerous animals must often be shot from moderate ranges, necessitating the use of a telescopic sight. But, in those same situations, the user may be unexpectedly confronted by a charging animal at close range. In such an emergency, the telescopic sight is a great hindrance and the open sights are preferable. Thus, a system giving the user an instant choice between the telescopic sight or the open sights is very desirable.
Additionally, users typically must initially locate the target using the naked eye because thick brush and trees make using the telescopic sight impractical. The user must first locate the target with the naked eye, then raise the rifle and try to find the target within the telescopic sight. Because the telescopic sight has a narrow field of view, this operation is difficult. It is much easier to find the target using the open sights, because they do not restrict the user's field of view. Thus, a system allowing the user to locate the target with the open sights, and then transfer rapidly to the telescopic sight without moving the rifle is very desirable.
Several inventions have provided a clear optical path through the telescopic sight mounting hardware so that the open sights may still be used. Illustrating this technique are U.S. Pat. No. 4,299,044 to Johannsen (1981), and U.S. Pat. No. 4,688,345 to Kilgour (1987). Unfortunately, while the devices shown in '044 and '345 do allow the use of the open sights, the user's field of view is still largely obscured by the telescopic sight, and sighting a moving target is therefore very difficult.
Another approach well-known in the prior art is to offset the telescopic sight to one side. Illustrating this configuration are U.S. Pat. No. 2,449,551 to Garand (1948), U.S. Pat. No. 3,724,800 to Rubin (1973), and U.S. Pat. No. 3,986,285 to Krisay (1976). The devices shown in '800 and '285 are uniquely adopted to Winchester-type lever action rifles, sometimes called "cowboy rifles." They require the rifle to have a large planar vertical surface on one side of the receiver, making these inventions difficult to apply to other types of rifles. For example, there is no planar surface on a bolt-action rifle. Additionally, both inventions have separate base pieces and telescopic sight attachment rings, making the overall structure less rigid. While this loss of rigidity is not a huge concern for low-recoiling "cowboy rifles", it is a big concern for the heavier calibers addressed by the proposed invention. Another disadvantage shown in '800 and '285 is that both devices position the telescopic sight in a high position, thereby greatly obscuring the user's field of view when employing the open sights.
The '551 patent to Garand may reasonably be applied to a military automatic rifle, such as the U.S. Rifle Cal. 30, M1, for which it was designed. It could be more broadly applied to bolt action rifles. Unfortunately, the mounting system shown in '551 requires the drilling of a large hole through the side of the receiver and barrel, the placement of a dowel pin therein, and the machining of a slot on the opposite side of the receiver. For use on a bolt-action rifle, the device would require the removal of a large piece of the stock to gain access to the receiver side. These operations are well beyond the capabilities of most rifle owners, and would result in the partial disfigurement of the rifle. The '551 device also uses a separate base piece and telescopic sight attachment assembly, resulting in the same loss of rigidity mentioned previously. Finally, like the '285 and '800 patents, the '551 device mounts the telescopic sight in a high position, causing the same field of view obstruction explained previously.
The known methods for mounting an offset telescopic sight are therefore limited in that they: (1) Have separate base pieces and telescopic sight attachment assemblies, resulting in a loss of rigidity; (2) Are uniquely adopted to a specific type of rifle; (3) Mount to the side of the receiver, which in many instances would require the removal of a portion of the stock and disfigurement of the rifle; and (4) Mount the telescopic sight relatively high, which greatly obscures the user's field of view when employing the open sights.